1)
Why does the Torah repeat
1.
Rashi: To teach us that if the fish had fins and scales in the water, it is Tahor, even though it shed them upon leaving the water.
2)
Why does the Torah insert the (otherwise superfluous) word "ba'Mayim"?
1.
Sifra: To teach us that if a fish sheds its fins and scales in the water it is nevertheless KAsher. 1
1
See Torah Temimah, note 46.
3)
Why does the Torah add "Sheketz Hu Lachem"?
